Electric machines typically include a stator assembly having one or more stator windings, and a rotor assembly rotatably mounted within the stator assembly. It is also common for electric machines to include clamshell-type housings that surround or enclose the stator assembly. To connect the stator windings to an external power source, electrical connectors or leads are commonly inserted through an open-ended notch formed in one of the housing's clamshell halves. If the notch is not adequately sealed, however, the notch provides ingress for moisture and foreign objects and debris, such as dirt and oil. Therefore, many electric machines include some means of sealing the notch to thereby protect the internal machine components from exposure to the exterior environment.
For example, FIGS. 1 through 6 illustrate a grommet 10 that can be positioned within an open-ended notch 14 (FIG. 5) defined by the one of the housing portions 18, 22 of a clamshell-type housing 26 (FIG. 6). As shown, the grommet 10 includes a groove 30 for receiving the housing wall 34. The grommet 10 can be retained within the open-ended notch 14 by sandwiching the grommet 10 between the upper and lower housing portions 18 and 22.
While grommets such as the grommet 10 shown in FIGS. 1 through 6 have worked well for their intended purpose, the inventors hereof have recognized that it would be desirable to have a grommet that can be inserted into a hole defined and surrounded by a wall of only one of the housing portions such that the hole has a perimeter with a closed geometry (in contrast to an open-ended notch), thereby allowing each housing portion to have a full uninterrupted hoop that is not impinged by the hole.